Crystallization is a solid-liquid separation technique, in which mass transfer of solute from liquid solution (parent phase) to a pure solid crystalline phase occurs (Figure 1). It is used to purify solid compounds. Cystallization is the oldest method for recovering solids from a solution. Fractional crystallization is a step-wise separation technique, which relies upon liquid-solid … Read More

Fractional distillation

Fractional distillation is a process to separate mixtures of volatile liquids and miscible liquids. It is commonly used to separate various components (difference in boiling point is less than 25oC) of a mixture depending upon their boiling points. Principle Involved If a liquid is heated in closed container, some molecules present at the surface of … Read More


Osmosis is a movement of water from region of high water concentration to region of low water concentration through a semi-permeable membrane until a state of dynamic equilibrium is reached (Figure 1). It is a passive process.  Water molecules are free to pass across the cell membrane in both directions. As the concentration of water … Read More

Freeze Drying

Freeze Drying is also known as Lyophilization or cryo-dessication. It is a process for removing water from the substance by the process of dehydration under vacuum while substance is in frozen state. Lyophilization technology is used to freeze-dry products, such as biologicals, bacterial cultures, analytical chemistry moieties, and therapeutic molecules (e.g., antibodies, vaccines, drugs, and … Read More